40mm or 50mm help


Well-Known Member
Jan 20, 2004
Blackfoot, Idaho
What are the advantages of 50mm over a 40mm? His will be a 3x9, or 4x12. Thanks

There is no short way, that I know of, to fully explain the answer for all conditions.

But. . . if shooting at 3 and 4x (lowest power) the difference won't be noticeable . . . much.

Before sun rise and after sun set and at higher magnifications the difference will be very noticeable and always favor the 50mm if a quality scope.

Scot E

Well-Known Member
Mar 1, 2008
SW Idaho
You will get a lot of varying opinions here in part because everybody's eyes are different and also because different power settings affect outcome. But generally speaking, if you compare equal quality glass with them both on the same power you will gain a few more minutes at dusk and dawn. In my experience it is less than 10 minutes and more like 5 or 6 minutes.

The advantage of the 50 comes in if you need high power in the last few minutes of light. Otherwise, there isn't a lot of benefit. There are drawbacks however, like a higher mount (harder for good cheek weld), and heavier scope.

Scot E.


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